A wide variety of exercises are known which create so-called cross resistance in selected muscles and which particularly produce alternating compression and tension in the abdominal muscles and the oblique muscles for the strengthening thereof and to reduce the waist line. The simplest form of such an exercise is the so-called torso or waist twist.
In performing this exercise, the exerciser may either extend the arms straight out or more may bend the arms at the elbows locking the hands together at the rear of the neck or head. In either event, the exerciser firmly plants the feet on the floor and begins to alternately twist the upper torso clockwise and counterclockwise. As a result of this alternate twisting, abdominal and oblique muscles on one side of the body compress, thus "pulling" the torso in one rotational direction, while the muscles on the other side are extended by this rotational action. Upon rotation stopping, the exerciser rotates in the opposite direction thus reversing the compressive and tensile effects on the affected muscle groups.
The effects of the above exercise may be accentuated, for example, by beginning the twisting action with the arms bent and the hands locked behind the head and by subsequently fully stretching the arms outwardly. This later action has the effect of increasing the rotative inertia of the exerciser, thereby requiring more force to both start and to stop the rotating action.
Along these lines, those engaged in exercise and weight lifting have for many years known that the addition of mass to the upper torso can further increase the force necessary to start and stop twisting. Such force addition has been achieved in the past by, for example, the exerciser carrying on the shoulders, and maintaining in place with the hands, an elongated member such as a broomstick, pole or weight lifting bar. See, for example, U.S. Pat. Nos. 4,518,162 and 4,770,414. These two patents illustrate more or less straight bars similar to poles or weight bars which contain a variety of padding and weight-varying adjustments. In both of these patents the exercise bars are essentially straight with the user grasping them at or near their ends with the hands of the outstretched arms.
The bar of the above mentioned U.S. Pat. No. 4,770,414 while essentially straight may include a central bend and bends at its extremities thereby increasing the comfort with which the bar may be rested on the shoulders at the back of the neck of the user and facilitating grasping of the bar at its extremities.
U.S. Pat. No. 3,820,781 illustrates an essentially straight bar which has a semi-circular yoke at its midsection for more comfortable resting at the back of the neck and on the shoulders of the users. FIG. 1 of the '781 patent illustrates the traditional use in the prior art of a straight bar such as a broomstick or a weight bar.
U.S. Pat. 4,257,591 illustrates an exercise bar which again is essentially straight but which contains at its extremities specially configured hand grasping members or handles.
In all of the patents noted above, the exercise bar is carried on top of the shoulders and behind the neck of the user. Further, in all of the above devices, the user grasps the bar at or near its extremities or rests the forearms on the top of the bar at or near such extremities. In both cases the arms are extended.
U.S. Pat. No. 4,863,158 illustrates an exercise bar having a central semi-circular portion for more comfortable resting of the bar behind the neck, and on the shoulders, of the user with forwardly extending handles for grasping by the user somewhat inwardly from the extremities of the bar. This bar also contains facilities for adding weights to the extremities thereof for increasing the mass carried and manipulated by the user.
U.S. Pat. No. 4,603,854 shows a trunk twist exercise device in which a straight bar having handles near its extremities also includes large area blades at either extremity. This bar is apparently rested across the shoulder blades of the user, a slightly curved portion permitting the bar to pass around the shoulders. The handles are grasped by the user with the arms nearly fully extended and trunk twists are undertaken. The blades increase wind resistance and thereby increase the force necessary to alternately twist the upper torso.
In none of the above described prior devices are the shoulders of the user locked together. Specifically, the shoulders may move independently to some extent. The use prior art torso twist bars thus permits the user to gain an "advantage" and to "cheat" in such a way as to not most efficiently exercise the abdominal and oblique muscles.
Further, prior art devices as described above, permit the arms, especially when outstretched, to "pull" the upper torso around, once again permitting the user to "cheat" and to not work the muscles of interest in the most efficient manner. The prior art devices are also to some extent uncomfortable to use. Specifically, if the mass of the bars is more than minimal, the weight thereof resting on the shoulders and behind the neck can produce muscle tension, strain and fatigue.
One object of the present invention is the elimination or amelioration of the disadvantages of the exercise bars of the prior art.